window.myLocalStorage = {
  setItem(key, value) {
    localStorage.setItem(key, JSON.stringify({
      date: new Date().toLocaleString(),
      data: value
    }))
  },
  getItem(key, def = null) {
    try {
      let value = JSON.parse(localStorage.getItem(key))
      return value ? value.data : def
    } catch (e) {
      return null
    }
  }
}